How to Create a Slice of Structs in Go

Create a slice of structs by declaring it with make or an empty literal, then append initialized struct instances to it. You can also initialize the entire slice in a single declaration if you know the elements upfront.

Here is the most common pattern using make and append for dynamic growth:

type User struct {
    Name string
    Age  int
}

// Create an empty slice with capacity for 2 elements
users := make([]User, 0, 2)

// Append new struct instances
users = append(users, User{Name: "Alice", Age: 30})
users = append(users, User{Name: "Bob", Age: 25})

// Access elements
fmt.Println(users[0].Name) // Output: Alice

If you know all elements at compile time, use a composite literal for a more concise definition:

type Product struct {
    ID   int
    Name string
}

// Initialize slice with predefined elements
products := []Product{
    {ID: 1, Name: "Laptop"},
    {ID: 2, Name: "Mouse"},
}

// Iterate over the slice
for _, p := range products {
    fmt.Printf("ID: %d, Name: %s\n", p.ID, p.Name)
}

Key distinctions to remember: make([]User, 0, 2) creates a slice with zero length but a capacity of 2, allowing efficient appends without immediate reallocation. Using []User{} creates an empty slice with zero length and zero capacity. When appending, always ensure the struct fields are initialized correctly; Go zero-values (empty strings, zero integers) apply automatically if you omit fields, but explicit initialization prevents ambiguity. Avoid creating a slice of pointers ([]*User) unless you specifically need to modify the underlying struct instances after appending or share them across functions, as passing structs by value copies the entire data structure.

A slice of structs is like a dynamic list of custom data items. You create it using make to reserve space in memory, similar to grabbing a tray with a set number of slots before you start filling it with items.